Using ground carbon in oil phase masterbatching

ABSTRACT

GROUND CARBONS FROM COKE OR COAL GROUND IN NONOXIDIZING ATMOSPHERE AND COATED WITH OIL CAN BE DISPERSED AND PROTECTED FROM OXIDATION BY MIXING THEM DIRECTLY INTO OIL PHASE MASTERBATCHES.

Feb. 8, 1972 w. w. GOTSHALL 3,540,940

USING GROUND CARBON IN OIL PHASE MASTERBATCHING Filed March 25, 1970 EXTENDER on.

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own/r01? WILLIAM w. GOTSHALL ATTORNEY United States Patent Office 3,640,940 Patented Feb. 8, 1972 3,640,940 USING GROUND CARBON IN OIL PHASE MASTERBATCHING William W. Gotshall, 3081 Walma Drive, Orchard Lake, Mich. 48034 Filed Mar. 25, 1970, Ser. No. 22,646 Int. Cl. C08c 11/18, 11/22; C08d 7/04 US. Cl. 260--33.6 AQ 7 Claims ABSTRACT THE DISCLOSURE Ground carbons from coke or coal ground in nonoxidizing atmosphere and coated with oil can be dispersed and protected from oxidation by mixing them directly into oil phase masterbatches.

CROSS REFERENCES TO RELATED APPLICATIONS The following US. patent application relates to the general field of the invention: US. patent application S.N. 22,644 filed Mar. 25, 1970 (Docket 690108A USA).

BACKGROUND OF THE INVENTION (1) Field of the invention (2) Description of the prior art The production of superior reinforcing agents by grinding cokes, chars, coals, and other carbonaceous materials in a nonoxidizing atmosphere, particularly in a fluid energy mill are disclosed in the aforementioned related U.S. patent applications as well as in US. Pats. 3,404,019 and 3,404,120 and divisional applications thereof, all to the inventor of the present application. Techniques for the production of masterbatches comprising conventional carbon blacks, vulcanizable elastomers, and other components of vulcanizable elastomeric compositions are taught in chapter 11 in Reinforcement of Elastomers by Gerard Kraus and Introduction to Rubber Technology by Maurice Morton, chapter 8, page 201.

The techniques of the above-mentioned US. patents require that carbonaceous material be ground in a nonoxidizing atmosphere and then be protected from oxygenation of the surface until it is compounded into a vulcanizable elastomeric composition. Preferably, this protection is accomplished by coating the individual particles with solid or liquid barriers against oxygenation. Normally, this process requires a grinding mill, a classifier, a dust collector, a mixer in which the particles are coated under an inert atmosphere, at pelletizer to render the carbon particles more convenient to handle, in some cases a bagging apparatus, and a second mixer in which the vulcanizable elastomeric composition is compounded. All of this apparatus requires substantial capital investment, particularly since the apparatus (excluding the pelletizer and second mixer) must generally operate under a nonoxidizing atmosphere. Further, the freight rate for transportation of finished carbon blacks is substantially higher than that for the carbonaceous materials from which they are made according to the aforementioned US. patents.

SUMMARY (1) General statement of the invention The present invention, by intercombining certain steps of the masterbatching and carbon pulverizing processes, provides a masterbatch composition to which only accelerators and sulfur need be added prior to vulcanizing. At the same time, the invention minimizes the chances for deleterious oxygenation of the carbon surfaces and reduces the number of components and the capital investment required. Further, the present invention permits shipping the carbonaceous raw materials to a relatively inexpensive combination carbon-pulverizing and masterbatching facility which can be located at the masterbatching plant to avoid more expensive shipment of the finished carbon reinforcement agents.

In the practice of the invention, selected coke or coal is ground under a nonoxidizing atmosphere in a fluid energy mill and particles in the desired size range are substantially continuously contacted with conventional extending oils to form a slurry which is mixed with a .water emulsion of vulcanizable elastomer and surfactant to form a masterbatch. After coagulation and dewatering, the masterbatch is ready for addition of sulfur, accelerators and other desired modifying ingredients and fabrication into finished rubber products. The required apparatus omits the dust collector and coating mixer and their related inert atmosphere accessories and instead connects an oil scrubber to the outlet of the classifier to form the slurry substantially continuously and avoid significant oxygenation of the carbon surfaces.

(2) Utility of the invention The masterbatches prepared by the processes and apparatus of the present invention are useful in the manufacture of a wide variety of elastomeric products including mechanical rubber goods, tire carcasses and tread stocks, rubber extrusions, and similar materials made from vulcanizable elastomers such as natural and synthetic rubber, styrene-butadiene copolymer, butadieneacrilonitrile copolymer, butyl rubber, ethylene-propylenediolefin terpolymer, polyisoprene, vulcanizable polymeric elastomeric material containing double bonds and derived from chloroprenes or fluoroprenes.

BRIEF DESCRIPTION OF THE DRAWING The drawing is a schematic representation of the apparatus of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) Starting materials (a) Carbon materials.Carbonaceous materials suitable as starting materials for the present invention include delayed petroleum coke, fluid petroleum coke, anthracite coal, coke derived from coal, char, e.g. nonagglomerating materials derived from coal or by the techniques of copending application S.N. 22,648 filed Mar. 25, 1970 (Docket 690112-A-USA). Preferably the carbonaceous materials should contain from about 0.1 to about 10, more preferably from 1 to about 8, and most preferably from 2 to about 6% by weight volatile combustible matter based on the weight of carbon. Generally from 25 to 150, more preferably from about 25 to about 400, more preferably 40 to 200, and most preferably from 50 to parts by weight of carbon will be employed for each part by weight of elastomer in the finished masterbatch (phr.).

(b) Vulcanizable elast0mers.Vulcanizable elastomers in general may be employed, but preferred among these will be those mentioned above under Utility, and most preferred are styrene-butadiene copolymer (SBR), and butyl rubber.

(c) Surfactanfs.-Conventional surfactants, e.g. sodium lignin sulfonate or rosin acid soap which are utilized for the preparation of aqueous emulsions or vulcanizable elastomers in conventional masterbatching will be employed. About 0.25 to about 10, more preferably from about 0.5 to about 5, and most preferably from about 1 to about 3 parts of surfactant per hundred parts by weight of carbon will be employed.

(d) Extender oils.Conventional extender oils, e.g. naphthenic, aromatic, or highly aromatic oils may be utilized with the present invention in the amounts normally used when employing conventional carbon blacks in the formulations. Extending oil loadings of from to about 75, more preferably to 50, and most preferably to parts per hundred parts of elastomer (phr.), can be utilized with the present invention. In general, the ex tender oils will be of the conventional types discussed in the aforementioned text by Morton and the references cited therein, particularly in chapter 7.

(2) Apparatus (a) The preferred grinding mills for pulverizing the carbonaceous material are fluid energy mills of the type commonly referred to as ,hurricane mills, e.g. the Model No. 30-10 mill manufactured by Majac, Inc. of Sharpsburg, Pa. The fluid energy mills can operate on a wide variety of inert, non-oxiding atmosphere. By nonoxidizing atmosphere is meant herein, media which do not contain substantial quantities of free oxygen. Steam is the most preferred grinding media from the standpoint of economy, but nitrogen, helium, hydrogen, argon, and a wide variety of other gases commonly thought of as inert or reducing, may be utilized. For maximum economy in grinding, gases of lower molecular weights, e.g. hydrogen and steam, are preferred.

The autogenous grinding mill is conventionally operated, preferably at temperatures of from about 350 to about 800 F., more preferably from about 400 to about 700 F., and most preferably at 400-500 F. The classifier is operated to provide an average particle size (by Weight) of less than about 2.5 microns with 99% by weight of the product having particle size of less than 5 microns. More preferred ranges are average particle size of less than 1.5 and 99% by weight less than 3 microns.

The classifier is preferably a centrifugal type and is operated under nonoxidizing atmosphere. The scrubber can be of conventional design to provide intimate contact between the oil and the ground carbon exiting from the classifier. Similarly, the emulsion-slurry mixer can be of conventional design, preferably a venturi mixer to provide intimate contact between the carbon-containing oil slurry and the elastomeric emulsion. Conventional filters, surge tanks, and settling tanks may be employed.

(3 Example The invention will be more fully understood by reference to the following example which is to be included as merely illustrative thereof.

EXAMPLE I Referring to the drawing, a raw fluid coke produced by granulating a fluid petroleum coke of the type produced according the methods of A. Voorhies, Fluid Coking, Proceedings of the 4th World Petroleum Congress, Section III/F, page 360 and Petroleum Processing, March 1956, pages 135 to 137 is fed from bin 1 to a Model No. 30-10 mill 2, manufactured by Majac, Inc. of Sharpsburg, Pa. Steam is utilized as the grinding fluid and a sonic velocity at approximately 400 to 800 F. (after exiting from the nozzle) and 100 to 150 p.s.i.g. nozzle pressure is maintained in the grinding section of the mill. This particular mill has opposed nozzles which cause a stream of particles to impinge upon a second stream of paritclesv causing highly efficient autogenous grinding. This grinding process is continued with particles having an average particle size of below about 1.5 microns and 99% by weight having a particle size below about 3 microns being continuously withdrawn from the classier 3 of the Majac mill 2. Oversize particles are returned to the pulverizer for further grinding through conduit 4. Steam and ground carbon of the desired maximum particle size are propelled by steam pressure through conduit 5 to venturi scrubber 6 where the excess steam is exhausted through outlet 7 and the carbon particles are contacted with extender oil. Approximately 2# of oil are fed to the venturi scrubber for each pound of ground carbon entering the scrubber and the oil-carbon mixture exits through outlet 8 of the scrubber as a 33% carbon oil slurry, The slurry is stirred in an agitated surge tank 10. A pump 11 conveys the slurry into venturi mixer 12 where it is intimately mixed with an aqueous vulcanizable elastomeric emulsion consisting of 92-97% water, 2% sodium lignin sulfonate surfactant, and 5- 10% SBR. Approximately 0.75 pound of carbon in an oil slurry are fed for each pound of vulcanizable elastomer in an aqueous emulsion. The mixture exiting from the venturi mixer is then acidified to a pH in the range of 6.5 to 7.5 in order to coagulate the masterbatch from the excess water which is separated out by settling in tank 14 and filtering in filter 15. Masterbatch is then conventionally baled in baler 16 and stored until it is to be mixed with sulfur, accelerators and other ingredients and vulcanized into finished vulcanized elastomeric products.

(4) Modifications of the invention It should be understood that the invention iscapable of a variety of modifications and variations which will be made apparent to those skilled in the art by a reading of the specification and which are to be included within the spirit of the claims appended hereto. See, for example, the techniques of chapter 11, Reinforcement of Elastomers edited by Gerard Kraus, Interscience Publishers Div. of John Wiley & Sons, and references cited therein.

What is claimed is:

1. A process for the manufacture of masterbatches comprising vulcanizable elastomers, together with carbon particles having surfaces substantially free from oxygenation, said process comprising in combination the steps of:

(a) reducing the volatile combustibles content of a coke, char or coal to from about 0.1 to about 10% by weight volatile combustible matter based on the weight of carbon,

(b) grinding said coke, char or coal under a nonoxidizing atmosphere in a fluid energy mill,

(c) substantially continuously conveying particles having average diameters in the range of below about 2.5 microns from said fluid energy mill into a liquid scrubber,

(d) contacting said carbon particles with from- 10 to about parts of extended oil per parts of the vulcanizable elastomer in said liquid scrubber to form a slurry,

(e) forming a water emulsion of vulcanizable elastomer and about 0.25 to about 10 parts of a surfactant per 100 parts of the carbon in the carbon particleextender oil slurry,

(f) intimately admixing said slurry and said water emulsion to form a masterbatch slurry,

(g) adjusting the pH of said masterbatch slurry to be in the range of from about 5 to about 8, so as to cause the coagulation and precipitation of an intimate mixture of said vulcanizable elastomer and said carbon particles substantially free from oxygenation and removing excess water whereby there is formed a masterbatch suitable for compounding into elastomeric polymeric compositions wherein the carbon particles are present in amounts of from 6 25 to allajouth400 parts per hundred in the coagulated References Cited master atc 2. The process of claim 1 wherein the carbon particles UNITED STATES PATENTS comprise fluid Coke 3,131,160 4/1964 Alexander et al. 260-335 AQ '3. The process of claim 1 wherein the carbon particles 5 3,223,333 12/1965 Stephanofi 260415 comprise anthracite CoaL 3,404,019 10/1968 GOtShall 106- 307 4. The process of claim 1 wherein the carbon particles 3,404,120 10/1968 Gotshau 260-415 R comprise delayed petroleum coke.

5. The process of claim 1 wherein the carbon particles comprise coke derived from coal. 10 U S C1 X R 6. The process of claim 1 wherein the carbon particles comprise han 106--307; Z6Q-41.5 MP, 763

7. The process of claim 1 wherein the non-oxidizing atmosphere comprises superheated steam.

ALLAN LIEBERMAN, Primary Examiner Po-ww UNITED T STATES PATENT OFFICE CERTIFIQATE OF CQECTION Patent No. 316401940 Dated 1972 William w. Gotshall Inventor(s) It is. certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 2, lines 63-65: Should read: -based'on the weight of carbon. Preferably from about to about 400, more preferably from about 40 to about 200, and most preferably from about to about Signed and sealed this 29th day of January 197M.

(SEAL) Attest: I

EDWARD M.ELETCHER, JR. RENE D. TEGTMEYER Attesting Officer Acting Commissioner of Patents 

